can this be used just for making you anonymous while connected to the internet regardless of what programs on your computer are connecting to the internet without have to install the IM client and the file sharing component? can it be used like hotspot shield?
I don't think you can compare these products.
Hotspot shield is more comparable to TrustConnect.
These build a SSL encrypted tunnel to a VPN Head-end from there you enter the Internet with an IP address of the provider.
Hotspot claims your 'anonymous' browsing, but I don't think that's entirely true.
They provide you with a different IP but if your browser saves cookies or has other characteristics they you can still be tracked.
Say your browser has a unique User-Agent, or one of the plugins uses a unique string to check for updates etc, they could still match you regardless of your source IP.
Unite is to be used for secure IM (read encrypted traffic from clients to server and back).
And Peer-2-Peer VPN between you and other VPN users, it builds an encrypted 'network' between those active on the network(Unite group) based on a 5.x.y.z/8 subnet.